Insertion devices and methods

ABSTRACT

Devices and methods relating to analyte sensor insertion devices and methods are provided.

RELATED APPLICATION

The present application claims priority under 35 U.S.C. §119(e) to U.S. provisional application No. 60/941,060 filed May 31, 2007, entitled “Insertion Devices and Methods”, the disclosure of which is incorporated herein by reference for all purposes.

BACKGROUND

The detection of the level of analytes, such as glucose, lactate, oxygen, and the like, in certain individuals is vitally important to their health. For example, the monitoring of glucose is particularly important to individuals with diabetes. Diabetics may need to monitor glucose levels to determine when insulin is needed to reduce glucose levels in their bodies or when additional glucose is needed to raise the level of glucose in their bodies.

Devices have been developed for continuous or automatic monitoring of analytes, such as glucose, in bodily fluid such as in the blood stream or in interstitial fluid. Some of these analyte measuring devices are configured so that at least a portion of the devices are positioned below a skin surface of a user, e.g., in a blood vessel or in the subcutaneous tissue of a user.

There is a need for a small, comfortable device which may continuously monitor the level of an analyte, such as glucose, while still permitting the user to engage in normal activities. Continuous and/or automatic monitoring of the analyte may provide a warning to the user when the level of the analyte is at or near a threshold level. For example, if glucose is the analyte, then the monitoring device might be configured to warn the user of current or impending hyperglycemia or hypoglycemia. The user may then take appropriate actions.

One of the challenges associated with producing an effective and comfortable monitoring device is inserting the sensor of such a monitoring device into a user's skin. Since the monitoring devices are contemplated to be used by a user themselves, the insertion should be simple and should be easily performed by the user.

One option for inserting the sensor is to provide a pre-armed inserter. Such an inserter is “armed” by the manufacturer so that the user only has to actuate the inserter. In order to do this, the inserter with a sensor is already under a load. One of the problems with such an approach is that a percentage of such pre-armed inserters will fire before reaching the user (e.g., during shipping or the like). Such inserters are then useless to the user. Another problem is that since the inserter is armed by the manufacturer, it is only good for a single use. Accordingly, a new inserter is necessary each time a sensor is inserted into a user's skin.

SUMMARY

Embodiments of the present invention relate to a self-arming analyte sensor device and methods. Included are devices and methods of using a self-arming inserter for inserting a sensor into a person's skin. According to one embodiment the inserter includes an inserter housing adapted to receive a mount, a carrier supported by the inserter housing, an insertion tip carrying a sensor mounted on the carrier, a driver which drives the carrier and an actuator which actuates the driver. Embodiments include inserting a mount into an inserter housing to arm the inserter, actuating an actuator to drive the insertion tip and sensor at least partially into a person's skin.

BRIEF DESCRIPTION OF THE DRAWINGS

The above aspects and features of the present invention will be more apparent by describing certain embodiments of the present invention with reference to the accompanying drawings, in which:

FIG. 1 is a block diagram of an exemplary embodiment of a data monitoring and management system according to the present invention;

FIG. 2A is a side view of an exemplary embodiment of a sensor unit and FIG. 2B is a perspective view of an exemplary embodiment of the sensor unit;

FIG. 3 is a top view of an exemplary embodiment of a mount for the sensor unit of FIGS. 2A and 2B with the sensor placed on the mount after insertion;

FIG. 4 illustrates an exemplary embodiment of a self-arming inserter in the armed position;

FIG. 5 illustrates an exemplary embodiment of a carrier used in the self-arming inserter;

FIG. 6 illustrates an exemplary embodiment of the carrier used in the self-arming inserter and an introducer for introducing a sensor on the carrier;

FIG. 7 illustrates an exemplary embodiment of loading of the mount into the inserter housing;

FIG. 8 illustrates an exemplary embodiment of shifting the mount in the inserter housing;

FIG. 9 illustrates an exemplary embodiment of an inserter tip and insertion portion of a sensor;

FIG. 10A-10C illustrate exemplary embodiments of configurations of insertion tips and sensors;

FIG. 11 is a schematic diagram of an embodiment of an analyte sensor according to the present invention; and

FIGS. 12A-12B are a perspective view and a cross sectional view, respectively, of another embodiment an analyte sensor.

DETAILED DESCRIPTION

Before the present invention is described, it is to be understood that this invention is not limited to particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges as also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention, the preferred methods and materials are now described.

It must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise.

As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention.

The figures shown herein are not necessarily drawn to scale, with some components and features being exaggerated for clarity.

Embodiments include analyte monitoring devices and systems that include an analyte sensor—at least a portion of which is positionable beneath the skin of the user—for the in vivo detection, of an analyte, such as glucose, lactate, and the like, in a body fluid. Embodiments include wholly implantable analyte sensors and analyte sensors in which only a portion of the sensor is positioned under the skin and a portion of the sensor resides above the skin, e.g., for contact to a transmitter, receiver, transceiver, processor, etc. The sensor may be, for example, subcutaneously positionable in a user for the continuous or periodic monitoring of a level of an analyte in a user's interstitial fluid. For the purposes of this description, continuous monitoring and periodic monitoring will be used interchangeably, unless noted otherwise. The sensor response may be correlated and/or converted to analyte levels in blood or other fluids. In certain embodiments, an analyte sensor may be positioned in contact with interstitial fluid to detect the level of glucose, which detected glucose may be used to infer the glucose level in the user's bloodstream. Analyte sensors may be insertable into a vein, artery, or other portion of the body containing fluid. Embodiments of the analyte sensors of the subject invention may be configured for monitoring the level of the analyte over a time period which may range from minutes, hours, days, weeks, or longer.

Of interest are analyte sensors, such as glucose sensors, that are capable of in vivo detection of an analyte for about one hour or more, e.g., about a few hours or more, e.g., about a few days or more, e.g., about three days or more, e.g., about five days or more, e.g., about seven days or more, e.g., about several weeks or at least one month. Future analyte levels may be predicted based on information obtained, e.g., the current analyte level at time t₀, the rate of change of the analyte, etc. Predictive alarms may notify the user of a predicted analyte level that may be of concern in advance of the user's analyte level reaching the future level. This provides the user an opportunity to take corrective action.

Provided are devices and structures for inserting a sensor into a person's skin and particularly self-arming inserters for inserting analyte, e.g., glucose, sensors. Also provided are analyte sensor insertion methods. The exemplary embodiments described herein relate to an analyte sensor which is used as part of an analyte monitoring system using for the in vivo determination of a concentration of an analyte, such as glucose or lactate, in a fluid. However, the structures and methods of the present invention may be applied to other sensors which are at least partially inserted into the person's skin.

FIG. 1 shows a data monitoring and management system such as, for example, an analyte (e.g., glucose) monitoring system 100 in accordance with certain embodiments. Embodiments of the subject invention are further described primarily with respect to glucose monitoring devices and systems, and methods of glucose detection, for convenience only and such description is in no way intended to limit the scope of the invention. It is to be understood that the analyte monitoring system may be configured to monitor a variety of analytes at the same time or at different times.

Analytes that may be monitored include, but are not limited to, acetyl choline, amylase, bilirubin, cholesterol, chorionic gonadotropin, creatine kinase (e.g., CK-MB), creatine, creatinine, DNA, fructosamine, glucose, glutamine, growth hormones, hormones, ketone bodies, lactate, peroxide, prostate-specific antigen, prothrombin, RNA, thyroid stimulating hormone, and troponin. The concentration of drugs, such as, for example, antibiotics (e.g., gentamicin, vancomycin, and the like), digitoxin, digoxin, drugs of abuse, theophylline, and warfarin, may also be monitored. In those embodiments that monitor more than one analyte, the analytes may be monitored at the same or different times.

The analyte monitoring system 100 includes a sensor unit 101, a data processing unit 102 connectable to the sensor unit 101, and a primary receiver unit 104 which is configured to communicate with the data processing unit 102 via a communication link 103. In certain embodiments, the primary receiver unit 104 may be further configured to transmit data to a data processing terminal 105 to evaluate or otherwise process or format data received by the primary receiver unit 104. The data processing terminal 105 may be configured to receive data directly from the data processing unit 102 via a communication link which may optionally be configured for bi-directional communication. Further, the data processing unit 102 may include a transmitter or a transceiver to transmit and/or receive data to and/or from the primary receiver unit 104 and/or the data processing terminal 105 and/or optionally a secondary receiver unit 106.

Also shown in FIG. 1 is an optional secondary receiver unit 106 which is operatively coupled to the communication link and configured to receive data transmitted from the data processing unit 102. The secondary receiver unit 106 may be configured to communicate with the primary receiver unit 104, as well as the data processing terminal 105. The secondary receiver unit 106 may be configured for bi-directional wireless communication with each of the primary receiver unit 104 and the data processing terminal 105. As discussed in further detail below, in certain embodiments the secondary receiver unit 106 may be a de-featured receiver as compared to the primary receiver, i.e., the secondary receiver may include a limited or minimal number of functions and features as compared with the primary receiver unit 104. As such, the secondary receiver unit 106 may include a smaller (in one or more, including all, dimensions), compact housing or embodied in a device such as a wrist watch, arm band, etc., for example. Alternatively, the secondary receiver unit 106 may be configured with the same or substantially similar functions and features as the primary receiver unit 104. The secondary receiver unit 106 may include a docking portion to be mated with a docking cradle unit for placement by, e.g., the bedside for night time monitoring, and/or a bi-directional communication device. A docking cradle may recharge a power supply.

Only one sensor unit 101, data processing unit 102 and data processing terminal 105 are shown in the embodiment of the analyte monitoring system 100 illustrated in FIG. 1. However, it will be appreciated by one of ordinary skill in the art that the analyte monitoring system 100 may include more than one sensor unit 101 and/or more than one data processing unit 102, and/or more than one data processing terminal 105. Multiple sensors may be positioned in a user for analyte monitoring at the same or different times. In certain embodiments, analyte information obtained by a first positioned sensor may be employed as a comparison to analyte information obtained by a second sensor. This may be useful to confirm or validate analyte information obtained from one or both of the sensors. Such redundancy may be useful if analyte information is contemplated in critical therapy-related decisions. In certain embodiments, a first sensor may be used to calibrate a second sensor.

The analyte monitoring system 100 may be a continuous monitoring system, or semi-continuous, or a discrete monitoring system. In a multi-component environment, each component may be configured to be uniquely identified by one or more of the other components in the system so that communication conflict may be readily resolved between the various components within the analyte monitoring system 100. For example, unique IDs, communication channels, and the like, may be used.

In certain embodiments, the primary receiver unit 104 may include an analog interface section including an RF receiver and an antenna that is configured to communicate with the data processing unit 102 via the communication link 103, and a data processing section for processing the received data from the data processing unit 102 such as data decoding, error detection and correction, data clock generation, data bit recovery, etc., or any combination thereof.

In operation, the primary receiver unit 104 in certain embodiments is configured to synchronize with the data processing unit 102 to uniquely identify the data processing unit 102, based on, for example, an identification information of the data processing unit 102, and thereafter, to periodically receive signals transmitted from the data processing unit 102 associated with the monitored analyte levels detected by the sensor unit 101.

Referring again to FIG. 1, the data processing terminal 105 may include a personal computer, a portable computer such as a laptop or a handheld device (e.g., personal digital assistants (PDAs), telephone such as a cellular phone (e.g., a multimedia and Internet-enabled mobile phone such as an iPhone or similar phone), mp3 player, pager, and the like), drug delivery device, each of which may be configured for data communication with the receiver via a wired or a wireless connection. Additionally, the data processing terminal 105 may further be connected to a data network (not shown) for storing, retrieving, updating, and/or analyzing data corresponding to the detected analyte level of the user.

The data processing terminal 105 may include an infusion device such as an insulin infusion pump or the like, which may be configured to administer insulin to users, and which may be configured to communicate with the primary receiver unit 104 for receiving, among others, the measured analyte level. Alternatively, the primary receiver unit 104 may be configured to integrate an infusion device therein so that the primary receiver unit 104 is configured to administer insulin (or other appropriate drug) therapy to users, for example, for administering and modifying basal profiles, as well as for determining appropriate boluses for administration based on, among others, the detected analyte levels received from the data processing unit 102. An infusion device may be an external device or an internal device (wholly implantable in a user).

In certain embodiments, the data processing terminal 105, which may include an insulin pump, may be configured to receive the analyte signals from the data processing unit 102, and thus, incorporate the functions of the primary receiver unit 104 including data processing for managing the user's insulin therapy and analyte monitoring. In certain embodiments, the communication link 103 as well as one or more of the other communication interfaces shown in FIG. 1, may use one or more of: an RF communication protocol, an infrared communication protocol, a Bluetooth® enabled communication protocol, an 802.11x wireless communication protocol, or an equivalent wireless communication protocol which would allow secure, wireless communication of several units (for example, per HIPAA requirements), while avoiding potential data collision and interference.

FIGS. 2A and 2B illustrate an exemplary embodiment of the sensor unit 101 in more detail. Sensor unit 101 may be part of a self-arming insertion system, as described below. The sensor unit 101 includes a sensor 42 which is to be partially inserted into a person's skin S. Additionally, the sensor unit 101 has a body having a mount 50 with arms 52 and a transmitter housing 55. The transmitter housing 55 may be attached to the mount 50 after the mount is secured to the user's skin and the sensor 42 has been inserted into the user's skin. An interconnector 54 connects the transmitter housing 55 with the sensor 42 and a seal 53 provides a watertight seal at the interconnection. The sensor unit 101 may also include a temperature module 56. Also, the sensor unit 101 may be secured to the user's skin S with an adhesive 58 provided on the bottom of the mount 50.

FIG. 3 is a top view of the control sensor. As shown in FIG. 3, the mount 50 includes a hole 51 for the sensor 42 so that the sensor 42 may pass through the mount into the user's skin S.

FIGS. 4-6 illustrate an exemplary embodiment of a self-arming inserter 70 to insert a sensor such as sensor 42 into a user's skin and attach the mount 50 of the sensor unit 101. The inserter 70 includes a housing 71 and a carrier 72 supported on the housing. A driver 82 is biased against the carrier 72. In this exemplary embodiment, the driver 82 is a drive spring, however other drivers are contemplated as well. As shown in detail in FIG. 5, the carrier 72 includes arms 78 and hooks 76. As seen in FIG. 4, the hooks 76 engage with protrusions 73 of the housing. The engagement of the hooks 76 with the protrusions 73 maintains the position of the carrier 72 against the force of the drive spring 82. The inserter 70 also includes an actuator 84 which retracts the protrusions 73, which in turn releases the carrier 72.

An introducer/inserter tip 120 may be supported on the carrier 72 to aid in the puncturing of a person's skin and guiding the sensor 42 at least partially into the skin. As shown in FIG. 5, the sensor 42 is attached to, or otherwise carried by, the carrier 72 at the inserter tip 120. Alternatively, the sensor may be directly attached to the carrier 72 and/or the sensor 42 may itself be the introducer/inserter tip. FIG. 6 shows one arrangement of the sensor 42 on the inserter tip 120.

As is also shown in FIG. 4, the inserter further includes a mount 50 which includes arms 52. With reference to FIG. 4, the arms 78 of the carrier 72 face the arms 52 of the mount 50. In this exemplary embodiment the mount 50 is a mount for the sensor unit 101 described above. However, the mount may also be a mount for other elements or units. For example, it may be a mount for another element of the analyte monitoring system 100, such as the data processing unit 102. The mount could also be a mount for multiple elements, such as both the sensor unit 101 and the data processing unit 102, or may be a mount for something other than an analyte monitoring unit.

FIGS. 7 and 8 illustrate the automatic loading (“arming”) and operation of the inserter 70. As described above, the mount 50 includes arms 52 and the carrier includes arms 78. The device is positioned so that the drive spring 82 is at least partially extended and the carrier 72 is near or at the bottom of the inserter housing 71. The inserter housing 71 is placed on the mount so that the mount arms 52 engage the carrier arms 78 and push the carrier farther into the interior of the housing 71. This may be done before or after the mount 50 is attached to the user's skin. Pushing the carrier 72 up the inserter housing 71 compresses the drive spring 82.

The carrier 72 is pushed into the interior of the inserter housing 71 a sufficient amount such that the carrier hooks 76 are caught by the protrusions 73 on the inserter housing 71. Since the drive spring 82 is now in a compressed position ready to drive the carrier 72, the inserter 70 is now armed. Accordingly, the single act of affixing the inserter to the patient, e.g., mating the inserter with the mount, arms the system.

After the inserter is armed, the carrier and the mount are shifted with respect to one another. This allows the mount arms 52 and the carrier arms 78 to be unaligned. When the arms 52, 78 are aligned, the mount 50 and the carrier 72 move together, as described above. This allows the mount 50 to push the carrier further into the interior of the housing 71 and arm the inserter 70 when the mount 50 is inserted into the housing 71. However, in order to actuate the device, the carrier 72 is moved relative to the mount 50 so that the arms 52, 78 do not undesirably interfere with one another. Accordingly, shifting the mount 50 with respect to the carrier 72 allows the carrier 72 to move downwardly under the force of the drive spring 82 without immediately contacting the mount arms 52. It is also noted that the inserter tip 120 and sensor 42 of the exemplary embodiment are longer than the arms 78 of the carrier 72 so that the insertion tip 120 and sensor 42 may pierce and travel into the user's skin while the arms are stopped at the skin by the mount, the skin itself, or some other mechanism.

This shifting may be performed by shifting the mount 50 relative to the inserter housing 71 or vice versa. Alternatively, the carrier 72 may be shifted with respect to the housing 71. Or there may be some combination of both. After the shift takes place, the inserter tip 120 and sensor 42 are aligned with the mount hole 51.

The inserter may then be actuated, e.g., by the use of an actuation button 84, or the like. The actuation may occur in a variety of different manners. For example, the protrusions 73 may be functionally connected to an actuation button 84, whereby depressing the actuation button 84 retracts the protrusions 73 to release the carrier 72 so that the carrier 72 may be driven by the drive spring 82. Thus, when the actuator button 84 is depressed, the protrusions 73 are retracted. The hooks 76 are then disengaged from the protrusions 73 and the drive spring 82 pushes the carrier towards the mount 50. Alternatively, the inserter may be designed such that the actuation button 84 causes the hooks 76 to bend over the protrusions 73 so that the carrier 72 is driven by the drive spring 82 without retracting the protrusions 73. This may be accomplished by, for example, causing a retraction or bending of the hooks 76 so that they move past the protrusions 73. Alternatively, actuating the actuation button 84 may impart an extra force on the carrier 72 sufficient to cause the hooks 76 to bend and slide past the protrusions 73.

At least before actuating the inserter, the mount 50 is placed on or near a user's skin. Actuating the inserter by depressing the actuation button 84 causes the carrier 72 to be driven by the driver 82 towards a user's skin. Since the inserter tip 120 and the sensor 42 are aligned with the mount hole 51, they pass through the hole 51 and into the user's skin. The mount 50 has an adhesive 58 or other attachment means on its base. Accordingly, the sensor is inserted into the user's skin and the mount is secured on the user's skin.

The sensor 42 may include optional features to facilitate insertion of an implantable sensor 42, as shown in FIG. 9. For example, the sensor 42 may be pointed at the tip 123 to ease insertion. In addition, the sensor 42 may include a barb 125 which assists in anchoring the sensor 42 within the tissue of the user during operation of the sensor 42. The barb 125 may be designed to be small enough that no clinically significant damage is caused to the subcutaneous tissue when the sensor 42 is removed for replacement.

The insertion tip 120 may have a variety of cross-sectional shapes, as shown in FIGS. 10A, 10B, and 10C. The insertion tip 120 illustrated in FIG. 10A is a flat, planar, pointed strip of rigid material which may be attached or otherwise coupled to the sensor 42 to ease insertion of the sensor 42 into the skin of the user, as well as to provide structural support to the sensor 42 during insertion. The insertion tip 120 of FIGS. 10B and 10C are U, C, L or V-shaped implements that support and guide the sensor 42 and puncture the skin to limit the amount that the sensor 42 may bend or bow during insertion. The cross-sectional width 124 of the insertion tips 120 illustrated in FIGS. 10B and 10C may be about 1 mm or less, e.g., about 700 μm or less, e.g., about 500 μm or less, e.g., about 300 μm or less. The cross-sectional height 126 of the insertion tip 120 illustrated in FIGS. 10B and 10C may be about 1 mm or less, e.g., about 700 μm or less, e.g., about 500 μm or less.

Once the sensor 42 and mount 50 are secured to the user's skin, the inserter housing 71 and carrier 72 may be lifted away from the skin. The inserter tip 120 may also be designed to remain with the carrier 72 and be lifted away with the housing after the sensor is inserted. If the sensor 42 includes the optional barb 125, then this structure may also facilitate the retention of the sensor 42 within the interstitial tissue as the barb catches in the tissue. The inserter 70 may be reloaded with another sensor 42 and possibly also another inserter tip/introducer 120 and re-armed by another mount 50. The same mount 50 may also be reloaded into the inserter housing 71 so that it is also reused. Accordingly, the inserter 70 of the exemplary embodiment is self-arming and reusable.

The driver may produce a speed designed to minimize trauma and/or pain. For example, a speed of less than about 2 m/s may be used in certain embodiments. Speeds greater than about 2 m/s may create trauma in the user's skin. Also, lower speeds require less force from the driver. Accordingly, a drive spring 82 with a lower spring constant may be used or the spring may be compressed to a lesser degree than with higher insertion speeds. This makes it easier for a user to arm the device and less likely that the inserter 70 will misfire.

As described above, the mount 50 may be a mount for a sensor unit 101. Accordingly, other elements may be integral to the mount 50 or attached to the mount once the sensor 42 is inserted into the user's skin. Alternatively, the mount 50 may serve as a mount for other devices or may simply serve to support the sensor 42. Also, the sensor 42 has been described as an analyte monitoring sensor for use with an analyte monitoring system 100. However, the sensor 42 is not limited to this particular function and use. The sensor 42 may be another type of sensor. Furthermore, the inserter 70 has been described with reference to exemplary embodiments for inserting a sensor 42. However, the inserter 70 may be used to insert another device or element instead of a sensor 42, particularly devices or elements which are designed to be at least partially inserted into a person's skin.

The inserter 70 described above may also be part of a kit. For example, the kit may include the inserter housing 71 and the mount 50. The inserter parts included in the kit would operate as described above with reference to FIGS. 7 and 8. That is, the user would mate the mount 50 with the inserter housing 71 to arm the inserter. The kit could also include additional elements. For example, the kit may include multiple sensors rather than just a single sensor 42. The kit may also include multiple inserter tips 120. Including multiple sensors 42 and/or inserter tips 120 would allow for these parts to be replaced, so that the kit would provide for multiple usages of the inserter. Of course, the kit could also include only a single sensor 42 or insertion tip 120. The kit may also include the other parts of the analyte monitoring system. For example, the kit may include a transmitter housing 55 which can be connected to the housing. The kit may also include the other components described with respect to FIG. 1 above.

Also provided is a method of manufacturing the inserter 70 described above. Manufacturing the inserter includes manufacturing the inserter housing 71 and the mount 50 such that they are mateable, as described above. Particularly, they are manufactured so that when the mount 50 is mated with the inserter housing 71, the inserter is armed, as described with reference to FIGS. 7 and 8. The inserter housing 71 may also be manufactured to include the other elements described above, such as the carrier 72. The other components of the analyte monitoring system may also be manufactured to provide the functions described above.

FIGS. 11, 12A and 12B show exemplary embodiments of sensors which could be used as the sensor 42 in the exemplary embodiment of the inserter 70. FIG. 11 schematically shows an embodiment of an analyte sensor in accordance with the present invention. This sensor embodiment includes electrodes 401, 402 and 403 on a base 404. Electrodes (and/or other features) may be applied or otherwise processed using any suitable technology, e.g., chemical vapor deposition (CVD), physical vapor deposition, sputtering, reactive sputtering, printing, coating, ablating (e.g., laser ablation), painting, dip coating, etching, and the like. Materials include but are not limited to aluminum, carbon (such as graphite), cobalt, copper, gallium, gold, indium, iridium, iron, lead, magnesium, mercury (as an amalgam), nickel, niobium, osmium, palladium, platinum, rhenium, rhodium, selenium, silicon (e.g., doped polycrystalline silicon), silver, tantalum, tin, titanium, tungsten, uranium, vanadium, zinc, zirconium, mixtures thereof, and alloys, oxides, or metallic compounds of these elements.

The sensor may be wholly implantable in a user or may be configured so that only a portion is positioned within (internal) a user and another portion outside (external) a user. For example, the sensor 400 may include a portion positionable above a surface of the skin 410, and a portion positioned below the skin. In such embodiments, the external portion may include contacts (connected to respective electrodes of the second portion by traces) to connect to another device also external to the user such as a transmitter unit. While the embodiment of FIG. 11 shows three electrodes side-by-side on the same surface of base 404, other configurations are contemplated, e.g., fewer or greater electrodes, some or all electrodes on different surfaces of the base or present on another base, some or all electrodes stacked together, electrodes of differing materials and dimensions, etc.

FIG. 12A shows a perspective view of an embodiment of an electrochemical analyte sensor 500 having a first portion (which in this embodiment may be characterized as a major portion) positionable above a surface of the skin 510, and a second portion (which in this embodiment may be characterized as a minor portion) that includes an insertion tip 530 positionable below the skin, e.g., penetrating through the skin and into, e.g., the subcutaneous space 520, in contact with the user's biofluid such as interstitial fluid. Contact portions of a working electrode 501, a reference electrode 502, and a counter electrode 503 are positioned on the portion of the sensor 500 situated above the skin surface 510. Working electrode 501, a reference electrode 502, and a counter electrode 503 are shown at the second section and particularly at the insertion tip 530. Traces may be provided from the electrode at the tip to the contact. It is to be understood that greater or fewer electrodes may be provided on a sensor. For example, a sensor may include more than one working electrode and/or the counter and reference electrodes may be a single counter/reference electrode, etc.

FIG. 12B shows a cross sectional view of a portion of the sensor 500 of FIG. 12A. The electrodes 501, 502 and 503, of the sensor 500 as well as the substrate and the dielectric layers are provided in a layered configuration or construction. For example, as shown in FIG. 12B, in one aspect, the sensor 500, includes a substrate layer 504, and a first conducting layer 501 such as carbon, gold, etc., disposed on at least a portion of the substrate layer 504, and which may provide the working electrode. Also shown disposed on at least a portion of the first conducting layer 501 is a sensing layer 508.

A first insulation layer such as a first dielectric layer 505 is disposed or layered on at least a portion of the first conducting layer 501, and further, a second conducting layer 509 may be disposed or stacked on top of at least a portion of the first insulation layer (or dielectric layer) 505. As shown in FIG. 12B, the second conducting layer 509 may provide the reference electrode 502, and in one aspect, may include a layer of silver/silver chloride (Ag/AgCl), gold, etc.

A second insulation layer 506 such as a dielectric layer in one embodiment may be disposed or layered on at least a portion of the second conducting layer 509. Further, a third conducting layer 503 may provide the counter electrode 503. It may be disposed on at least a portion of the second insulation layer 506. Finally, a third insulation layer may be disposed or layered on at least a portion of the third conducting layer 503. In this manner, the sensor 500 may be layered such that at least a portion of each of the conducting layers is separated by a respective insulation layer (for example, a dielectric layer). The embodiment of FIGS. 12A and 12B show the layers having different lengths. Some or all of the layers may have the same or different lengths and/or widths.

In certain embodiments, some or all of the electrodes 501, 502, 503 may be provided on the same side of the substrate 504 in the layered construction as described above, or alternatively, may be provided in a co-planar manner such that two or more electrodes may be positioned on the same plane (e.g., side-by side (e.g., parallel) or angled relative to each other) on the substrate 504. For example, co-planar electrodes may include a suitable spacing there between and/or include dielectric material or insulation material disposed between the conducting layers/electrodes. Furthermore, in certain embodiments one or more of the electrodes 501, 502, 503 may be disposed on opposing sides of the substrate 504. In such embodiments, contact pads may be on the same or different sides of the substrate. For example, an electrode may be on a first side and its respective contact may be on a second side, e.g., a trace connecting the electrode and the contact may traverse through the substrate.

The description herein is directed primarily to electrochemical sensors for convenience only and is in no way intended to limit the scope of the invention. Other sensors and sensor systems are contemplated. Such include, but are not limited to, optical sensors, calorimetric sensors, and sensors that detect hydrogen peroxide to infer glucose levels, etc. The sensor may be used as part of the sensor unit 101.

A glucose sensor insertion system in one aspect may include a mount configured to retain an inserter housing, the inserter housing being mateable with the mount and comprising a structure to carry a glucose sensor at least partially into a user's skin, where mating the inserter housing and the mount together arms the system.

A self arming inserter in accordance with another aspect may include an inserter housing to be received in a mount, a carrier supported by the inserter housing, a sensor mounted on the carrier, and a driver which drives the carrier, where inserting the inserter housing in the mount arms the driver.

The mount may include a mount base and mount arms and the carrier may include carrier arms.

The carrier may include a hook that engages a portion of the housing when driver is armed.

In a further aspect, an actuator may be provided which actuates the driver and wherein actuating the actuator releases the driver.

The driver may include a spring and wherein arming the inserter comprises compressing the spring.

The mount may include an inserter hole through which the sensor passes when the carrier is driven by the driver.

Further, the mount may be shiftable with respect to the housing after the mount is inserted into the housing.

The driver may be configured to drive the carrier at a speed of about 2 m/s or less.

Additionally, an inserter tip may be provided which supports the sensor on the carrier.

The sensor may attach to the mount after the driver drives the carrier.

Also, an adhesive may be provided on a surface of the mount.

A method of arming an analyte sensor insertion system in yet another aspect may include providing to a user an un-armed system that comprises an inserter housing and a mateable mount, and mating the insertion housing and the mount together, whereby the mating arms the system.

A method of inserting an insertion tip using an inserter, the inserter including an inserter housing adapted to be received on a mount, a carrier supported by the inserter housing, an insertion tip mounted on the carrier, a driver which drives the carrier, and an actuator which actuates the driver, in yet still another aspect may include placing the inserter housing on the mount so that arms of the mount contact arms of the carrier, thereby moving the carrier in a direction of arming the driver, shifting the mount relative to the inserter housing so that the arms of the mount are unaligned with the arms of the carrier, placing the inserter such that the mount is adjacent to a person's skin, and actuating the actuator so that the driver drives the carrier and the insertion tip is inserted into the person's skin.

A sensor may be attached to the insertion tip and the sensor is also inserted into the person's skin.

The mount may include a base with a hole, wherein the insertion tip and the sensor pass through the hole before entering the person's skin.

The sensor may be an analyte monitoring sensor, including for example, a glucose sensor.

The method may also include securing the mount to the person's skin.

A self arming inserter in a further aspect may include an inserter housing to be received in a mount, a carrier supported by the inserter housing, a sensor mounted on the carrier, a driver which drives the carrier, and an actuator which actuates the driver, where inserting the inserter housing in the mount arms the driver, and actuating the actuator releases the driver which drives the carrier, whereby the sensor is inserted into a user's skin.

A glucose sensor insertion system kit in accordance with another aspect of the present disclosure includes a mount, an inserter housing, and a glucose sensor which can be carried at least partially into a user's skin by a structure in the inserter housing, wherein mating the mount and the inserter housing arms the glucose sensor insertion system.

A method of manufacturing a glucose sensor insertion system in accordance with still another aspect includes manufacturing a mount and manufacturing an inserter housing which is mateable with the mount and which comprises a structure to carry a glucose sensor at least partially into a user's skin, wherein mating the inserter housing and the mount arms the system.

Accordingly, while non-limiting exemplary embodiments of the invention have been described and illustrated above, it should be understood that these are examples of the invention and are not to be considered as limiting. It will be understood by those of ordinary skill in the art that additions, omissions, substitutions, and other modifications may be made without departing from the spirit or scope of the present invention. 

What is claimed is:
 1. A glucose sensor insertion system, the system comprising: a mounting unit configured to mate with an inserter, the inserter comprising a housing, a structure within the housing configured to carry a glucose sensor, and a driver within the housing to drive the glucose sensor at least partially into a user's skin; wherein when the inserter and the mounting unit are mated, the mounting unit causes the structure to be pushed into an interior of the inserter housing; wherein mating the inserter and the mounting unit together arms the system; wherein the mounting unit comprises a mount base and mount arms and the structure within the housing to carry the glucose sensor comprises carrier arms; and wherein the structure within the housing configured to carry the glucose sensor comprises a hook that engages a portion of the housing when the driver is armed.
 2. A self arming inserter comprising: an inserter housing to be received in a mounting unit; a carrier supported by the inserter housing; a sensor mounted on the carrier; and a driver which drives the carrier; wherein when the inserter and the mounting unit are mated, the mounting unit causes the carrier to be pushed into an interior of the inserter housing; wherein inserting the inserter housing in the mounting unit arms the driver; wherein the mounting unit comprises a mount base and mount arms and the carrier comprises carrier arms; and wherein the carrier comprises a hook that engages a portion of the housing when the driver is armed.
 3. The self arming inserter according to claim 2, further comprising an actuator which actuates the driver and wherein actuating the actuator releases the driver.
 4. The self arming inserter according to claim 3, wherein the driver comprises a spring and wherein arming the inserter comprises compressing the spring.
 5. The self arming inserter according to claim 2, wherein the mounting unit comprises an inserter hole through which the sensor passes when the carrier is driven by the driver.
 6. The self arming inserter according to claim 2, wherein the mounting unit is shiftable with respect to the housing after the mounting unit is inserted into the housing.
 7. The self arming inserter according to claim 2, further comprising an inserter tip which supports the sensor on the carrier.
 8. The self arming inserter according to claim 2, wherein the sensor attaches to the mounting unit after the driver drives the carrier.
 9. The self arming inserter according to claim 2, wherein an adhesive is provided on a surface of the mounting unit.
 10. The glucose sensor insertion system of claim 1, wherein the mounting unit comprises an adhesive on a surface of the mounting unit.
 11. The glucose sensor insertion system of claim 1, wherein the inserter further comprises an actuator, and wherein actuating the actuator releases the driver to drive the glucose sensor at least partially into the user's skin.
 12. The glucose sensor insertion system of claim 1, wherein the driver drives the glucose sensor at least partially into the user's skin at a speed of about 2 m/s or less.
 13. The self arming inserter according to claim 2, wherein the driver drives the carrier at a speed of about 2 m/s or less.
 14. A method of inserting a glucose sensor, the method comprising: coupling the glucose sensor with an introducer, the introducer configured to facilitate insertion of the glucose sensor through a skin layer; coupling the glucose sensor with an inserter; mating a mounting unit with the inserter, wherein mating the mounting unit with the inserter causes the glucose sensor to be pushed into an interior of the inserter and arms the inserter; actuating an actuator to drive the glucose sensor; and driving, using the inserter, the glucose sensor at least partially through the skin layer; wherein the sensor is mounted on a carrier that is supported by a housing of the inserter; and wherein mating the mounting unit with the inserter causes a hook on the carrier to engage a portion of the housing when the inserter is armed.
 15. The method of claim 14, wherein driving the glucose sensor at least partially through the skin layer includes driving the glucose sensor at a speed of about 2 m/s or less.
 16. A method comprising: receiving an inserter housing in a mounting unit; providing a carrier supported by the inserter housing; mounting a sensor on the carrier; coupling a driver to the carrier; pushing the carrier into an interior of the housing and arming the driver when the inserter housing is received in the mounting unit; engaging the carrier with a portion of the inserter housing when the driver is armed; actuating an actuator to release the driver; and driving, using the driver, the carrier; wherein the carrier comprises a hook that engages the portion of the housing when the driver is armed.
 17. The method of claim 16, wherein arming the driver comprises compressing the driver.
 18. The method of claim 16, further comprising attaching the sensor to the mounting unit after the driver drives the carrier.
 19. The method of claim 18, further comprising coupling a transmitter to the mounting unit.
 20. The method of claim 16, including driving, using the driver, the carrier at a speed of about 2 m/s or less. 